The RSPCA said brothers Derek and David Benton, from Ely, Cambridgeshire, hadn't been giving Rusty the right sort of diet before and he couldn't exercise because he has arthritis, which affects his legs.

But since he's slimmed down, his arthritis has got a lot better as he doesn't have so much weight to haul around.

New life

Rusty's vet said he'd made great progress: "He is a much happier and healthier dog now, his pain is well-controlled and he walks much better than he could before.

"Before his treatment and weight loss Rusty was the most disabled dog I have ever seen in practice. However, he now has a proper life again."